Distributed cloud-based dynamic name server surrogation systems and methods

ABSTRACT

A Dynamic Name Server (DNS) surrogation method, a DNS system, and a DNS server provide DNS surrogation which is the idea that if a user device sends a DNS resolution request to a given DNS server that server does not need to actually perform the recursion itself. A policy can be defined telling the server that first received the request to take other factors into account and “relay” or “surrogate” that request to another node. This additional node is called a “surrogate” and it actually performs the recursion therefore allowing the resolving party to perform proper localization, optimization, or any other form of differentiated resolution. This surrogation also distributes the job of actually performing resolution, which adds scalability to the DNS server or service itself. A network of “surrogate” resolvers is possible as well as the concept of every client needing DNS resolution can also become a surrogate.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present patent/application is a continuation of U.S. patentapplication Ser. No. 13/948,362, filed Jul. 23, 2013, and entitled“DISTRIBUTED CLOUD-BASED DYNAMIC NAME SERVER SURROGATION SYSTEMS ANDMETHODS,” the contents of which are incorporated by reference herein.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to computer networking systemsand methods. More particularly, the present disclosure relates todistributed cloud-based Domain Name Server (DNS) surrogation systems andmethods.

BACKGROUND OF THE DISCLOSURE

Each host connected to the Internet has a unique Internet Protocol (IP)address in textual form, translating it to an IP address (e.g.,205.186.173.184) is a process known as DNS resolution or DNS lookup.During DNS resolution, a program that wishes to perform this translationcontacts a DNS server that returns the translated IP address. Inpractice, the entire translation may not occur at a single DNS server;rather, a DNS server contacted initially may recursively call upon otherDNS servers to complete the translation. For a more complex UniformResource Locator (URL) such as www.site.com/home/products, the crawlercomponent responsible for DNS resolution extracts the host name—in thiscase www.site.com—and looks up the IP address for the host www.site.com.DNS resolution today takes place in a very static model. A clientrequests resolution for a given domain name via its configured DNSserver, the server recursively searches for that resolution, and thenreturns the result to the client.

A challenge occurs in that many Internet services today rely on DNS (andthe server recursion process) to provide localization of content as wellas to optimize content delivery. For example for google.com, therecursion process may return a different IP address for a user locatedin the U.S. or even for a specific location in the U.S. versus a user ina foreign country. Content is geo-localized or routed to the bestdestination based on the source IP address of the DNS server thatperformed the recursion. This is primarily because to localize oroptimize content based on DNS alone the only information present beyondthe domain name being resolved recursively is the IP address thatrequested the resolution. As a result to provide the best experiencepossible (localized or optimized content delivery) DNS serverstraditionally needed to be local to the clients that they are serving.Another challenge is how to effectively scale a DNS-policy driveninfrastructure that is capable of supporting tens or hundreds ofmillions of devices. On one hand, it is desired take all DNS trafficfrom a given device, all the time, to apply policy. On the other thehand, this must manage the load placed that infrastructure when it isadopted at any amount of scale. Having the ability to distribute theload becomes critical.

Finally organizations also provide split horizon/differentiated DNSresolution based on where the client is. For example, the resolution ofa particular domain name internal to a network may provide a differentIP address than if it originated outside that network. Differentiatedresolution can also occur in any application that needs to route trafficbased factors other than locality or optimization. As a result, whenbuilding a service that is inherently based on DNS, that service eitherneeds to be highly localized and massively distributed or have a way totake into account the need for localized recursion for requesteddestinations in the form of a policy. Additionally for the DNS serviceto remain operable it needs to scale elastically and without limit.

BRIEF SUMMARY OF THE DISCLOSURE

In an exemplary embodiment, a Dynamic Name Server (DNS) surrogationmethod includes receiving a DNS request at a DNS server; performing apolicy look up based on a plurality of factors related to the DNSrequest; surrogating the DNS request to one of a plurality of surrogatesbased on the policy look up; performing DNS resolution of the DNSrequest by the one of the plurality of surrogates; and providing aresult of the DNS resolution in response to the DNS request. The DNSsurrogation method can further include configuring a user device to usethe DNS server for DNS resolution; and performing the DNS resolution forthe user device by the one of the plurality of surrogates. The DNSsurrogation method can further include determining surrogation isrequired for the DNS request based on the policy look up. The DNSsurrogation method can further include performing the policy look up todetermine a location of a user device associated with the DNS request,configuration policy, status of the plurality of surrogates, andlocality of the plurality of surrogates. The DNS surrogation method canfurther include providing a request from the one of the plurality ofsurrogates to an authoritative DNS server associated with a domain nameof the DNS request. The DNS surrogation method can further includereceiving the result of the DNS resolution based on a location or sourceInternet Protocol address of the one of the plurality of surrogatesinstead of based on the DNS server. The one of the plurality ofsurrogates can include a user device associated with the DNS request.The plurality of surrogates can be geographically diverse andcommunicatively coupled to the DNS server thereby forming a distributedsecurity cloud network.

In another exemplary embodiment, a Dynamic Name Server (DNS) systemincludes a Dynamic Name Server (DNS) communicatively coupled to a userdevice; a policy data store communicatively coupled to the DNS; and asurrogate DNS communicatively coupled to the DNS; wherein the DNS isconfigured to: receive a DNS request from the user device; perform apolicy look up based on a plurality of factors related to the DNSrequest; and transmit the DNS request to the surrogate DNS based on thepolicy look up; and wherein the surrogate DNS is configured to: performDNS resolution of the DNS request; and provide a result of the DNSresolution to the user device. The user device can be configured to usethe DNS for DNS resolution, and wherein the DNS resolution is performedby the DNS surrogate. The DNS can determine surrogation is required forthe DNS request based on the policy look up. The policy look up candetermine a location of the user device associated with the DNS request,configuration policy, status of a plurality of surrogates including thesurrogate DNS, and locality of the plurality of surrogates. Thesurrogate DNS can be configured to provide a request to an authoritativeDNS server associated with a domain name of the DNS request. The resultof the DNS resolution can be based on a location or source InternetProtocol address of the surrogate DNS instead of based on the DNS. Thesurrogate DNS can include the user device associated with the DNSrequest. A plurality of surrogates including the surrogate DNS can begeographically diverse and communicatively coupled to the DNS therebyforming a distributed security cloud network.

In yet another exemplary embodiment, a Dynamic Name Server (DNS) includea network interface; a processor communicatively coupled to the networkinterface; memory storing instructions that, when executed, cause theprocessor to: receive a DNS request from a user device through thenetwork interface, wherein the user device is configured with anInternet Protocol address of the DNS for providing DNS resolution;perform a policy look up based on a plurality of factors related to theDNS request; and surrogate the DNS request to one of a plurality ofsurrogates based on the policy look up, wherein the one of the pluralityof surrogates performs the DNS resolution instead of the DNS. The policylook up can determine a location of the user device, configurationpolicy, status of the plurality of surrogates, and locality of theplurality of surrogates such that the one of the plurality of surrogatesis chosen based thereon. The one of the plurality of surrogates caninclude the user device associated with the DNS request. The pluralityof surrogates can be geographically diverse and communicatively coupledto the DNS thereby forming a distributed security cloud network.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated and described herein withreference to the various drawings, in which like reference numbers areused to denote like system components/method steps, as appropriate, andin which:

FIG. 1 is a network diagram of a distributed security system, and thelike;

FIG. 2 is a network diagram of the distributed security system of FIG. 1illustrating various components in more detail;

FIG. 3 is a block diagram of a server which may be used in thedistributed security system of FIG. 1 or standalone;

FIG. 4 is a block diagram of a mobile device which may be used in thesystem of FIG. 1 or with any other cloud-based system;

FIG. 5 is a network diagram of a cloud system;

FIG. 6 is a network diagram of a network with a distributed securitycloud providing DNS augmented security;

FIG. 7 is a flow diagram of a DNS surrogation method; and

FIG. 8 is a flow diagram of a DNS surrogation method showing activity inthe network of FIG. 6 and amongst the receiving DNS server and the DNSsurrogate server of FIG. 7.

DETAILED DESCRIPTION OF THE DISCLOSURE

In various exemplary embodiments, the present disclosure relates todistributed cloud-based Dynamic Name Server (DNS) surrogation systemsand methods. DNS surrogation is the idea that if a client sends aresolution request to a given DNS server, that server does not need toactually perform the recursion itself. A policy can be defined tellingthe server that first received the request to take other factors intoaccount and “relay” or “surrogate” that request to another server. Thisadditional server is called a “surrogate” and it will actually performthe recursion therefore allowing the resolving party to perform properlocalization, optimization, or any other form of differentiatedresolution. This surrogation also distributes the job of actuallyperforming resolution, which adds scalability to the DNS server orservice itself. A network of “surrogate” resolvers is possible as wellas the concept of every client needing DNS resolution can also become asurrogate adding tremendous elasticity to the service.

The concept of surrogating DNS requests to a network of surrogates isunique and has not been accomplished before. A real need for DNSsurrogation arises when building a cloud offering that is inherentlyreliant on DNS as a mechanism to provide service. Without surrogation, aDNS infrastructure must be built out in every region (city, country)that is serviced, which is a very costly endeavor. Surrogation allowsfor a DNS service to exist in a fewer number of sites while stillproviding results as if it in a greater number of sites whilemaintaining geographic localization. Surrogation also allows for adistributed method of providing DNS-based policy and resolution. Ifevery client receiving service also is a surrogate then the networkscales elastically with every client. Surrogation also allows for aclient to “fail open.” If the cloud service is unavailable to providepolicy to the request the client can fail open and still be operable.

Referring to FIG. 1, in an exemplary embodiment, a block diagramillustrates a distributed security system 100. The system 100 may, forexample, be implemented as an overlay network in a wide area network(WAN), such as the Internet, a local area network (LAN), or the like.The system 100 includes content processing nodes (PN) 110, thatproactively detect and preclude the distribution of security threats,e.g., malware, spyware, viruses, email spam, etc., and other undesirablecontent sent from or requested by an external system. The processingnodes 110 can also log activity and enforce policies. Example externalsystems may include an enterprise 200, a computer device 220, and amobile device 230, or other network and computing systemscommunicatively coupled to the system 100. In an exemplary embodiment,each of the processing nodes 110 may include a decision system, e.g.,data inspection engines that operate on a content item, e.g., a webpage, a file, an email message, or some other data or data communicationthat is sent from or requested by one of the external systems. In anexemplary embodiment, all data destined for or received from theInternet is processed through one of the processing nodes 110. Inanother exemplary embodiment, specific data specified by each externalsystem, e.g., only email, only executable files, etc., is processthrough one of the processing node 110.

Each of the processing nodes 110 may generate a decision vector D=[d1,d2, . . . , dn] for a content item of one or more parts C=[c1, c2, . . ., cm]. Each decision vector may identify a threat classification, e.g.,clean, spyware, malware, undesirable content, innocuous, spam email,unknown, etc. For example, the output of each element of the decisionvector D may be based on the output of one or more data inspectionengines. In an exemplary embodiment, the threat classification may bereduced to a subset of categories e.g., violating, non-violating,neutral, unknown. Based on the subset classification, the processingnode 110 may allow distribution of the content item, precludedistribution of the content item, allow distribution of the content itemafter a cleaning process, or perform threat detection on the contentitem. In an exemplary embodiment, the actions taken by one of theprocessing nodes 110 may be determinative on the threat classificationof the content item and on a security policy of the external system towhich the content item is being sent from or from which the content itemis being requested by. A content item is violating if, for any partC=[c1, c2, . . . , cm] of the content item, at any of the processingnodes 110, any one of the data inspection engines generates an outputthat results in a classification of “violating.”

Each of the processing nodes 110 may be implemented by one or more ofcomputer and communication devices, e.g., server computers, gateways,switches, etc., such as the server 300 described in FIG. 3. In anexemplary embodiment, the processing nodes 110 may serve as an accesslayer 150. The access layer 150 may, for example, provide externalsystem access to the security system 100. In an exemplary embodiment,each of the processing nodes 110 may include Internet gateways and oneor more servers, and the processing nodes 110 may be distributed througha geographic region, e.g., throughout a country, region, campus, etc.According to a service agreement between a provider of the system 100and an owner of an external system, the system 100 may thus providesecurity protection to the external system at any location throughoutthe geographic region.

Data communications may be monitored by the system 100 in a variety ofways, depending on the size and data requirements of the externalsystem. For example, an enterprise 200 may have multiple routers,switches, etc. that are used to communicate over the Internet, and therouters, switches, etc. may be configured to establish communicationsthrough the nearest (in traffic communication time, for example)processing node 110. A mobile device 230 may be configured tocommunicated to a nearest processing node 110 through any availablewireless access device, such as an access point, or a cellular gateway.A single computer device 220, such as a consumer's personal computer,may have its browser and email program configured to access the nearestprocessing node 110, which, in turn, serves as a proxy for the computerdevice 220. Alternatively, an Internet provider may have all of itscustomer traffic processed through the processing nodes 110.

In an exemplary embodiment, the processing nodes 110 may communicatewith one or more authority nodes (AN) 120. The authority nodes 120 maystore policy data for each external system and may distribute the policydata to each of the processing nodes 110. The policy may, for example,define security policies for a protected system, e.g., security policiesfor the enterprise 200. Example policy data may define access privilegesfor users, web sites and/or content that is disallowed, restricteddomains, etc. The authority nodes 120 may distribute the policy data tothe access nodes 110. In an exemplary embodiment, the authority nodes120 may also distribute threat data that includes the classifications ofcontent items according to threat classifications, e.g., a list of knownviruses, a list of known malware sites, spam email domains, a list ofknown phishing sites, etc. The distribution of threat data between theprocessing nodes 110 and the authority nodes 120 may implemented by pushand pull distribution schemes described in more detail below. In anexemplary embodiment, each of the authority nodes 120 may be implementedby one or more computer and communication devices, e.g., servercomputers, gateways, switches, etc., such as the server 300 described inFIG. 3. In some exemplary embodiments, the authority nodes 120 may serveas an application layer 160. The application layer 160 may, for example,manage and provide policy data, threat data, and data inspection enginesand dictionaries for the processing nodes 110.

Other application layer functions may also be provided in theapplication layer 170, such as a user interface (UI) front-end 130. Theuser interface front-end 130 may provide a user interface through whichusers of the external systems may provide and define security policies,e.g., whether email traffic is to be monitored, whether certain websites are to be precluded, etc. Another application capability that maybe provided through the user interface front-end 130 is securityanalysis and log reporting. The underlying data on which the securityanalysis and log reporting functions operate are stored in logging nodes(LN) 140, which serve as a data logging layer 160. Each of the loggingnodes 140 may store data related to security operations and networktraffic processed by the processing nodes 110 for each external system.In an exemplary embodiment, the logging node 140 data may be anonymizedso that data identifying an enterprise is removed or obfuscated. Forexample, identifying data may be removed to provide an overall systemsummary of security processing for all enterprises and users withoutrevealing the identity of any one account. Alternatively, identifyingdata may be obfuscated, e.g., provide a random account number each timeit is accessed, so that an overall system summary of security processingfor all enterprises and users may be broken out by accounts withoutrevealing the identity of any one account. In another exemplaryembodiment, the identifying data and/or logging node 140 data may befurther encrypted, e.g., so that only the enterprise (or user if asingle user account) may have access to the logging node 140 data forits account. Other processes of anonymizing, obfuscating, or securinglogging node 140 data may also be used.

In an exemplary embodiment, an access agent 180 may be included in theexternal systems. For example, the access agent 180 is deployed in theenterprise 200. The access agent 180 may, for example, facilitatesecurity processing by providing a hash index of files on a clientdevice to one of the processing nodes 110, or may facilitateauthentication functions with one of the processing nodes 110, e.g., byassigning tokens for passwords and sending only the tokens to aprocessing node so that transmission of passwords beyond the networkedge of the enterprise is minimized. Other functions and processes mayalso be facilitated by the access agent 180. In an exemplary embodiment,the processing node 110 may act as a forward proxy that receives userrequests to external servers addressed directly to the processing node110. In another exemplary embodiment, the processing node 110 may accessuser requests that are passed through the processing node 110 in atransparent mode. A protected system, e.g., enterprise 200, may, forexample, choose one or both of these modes. For example, a browser maybe configured either manually or through the access agent 180 to accessthe processing node 110 in a forward proxy mode. In the forward proxymode, all accesses are addressed to the processing node 110.

In an exemplary embodiment, an enterprise gateway may be configured sothat user requests are routed through the processing node 110 byestablishing a communication tunnel between enterprise gateway and theprocessing node 110. For establishing the tunnel, existing protocolssuch as generic routing encapsulation (GRE), layer two tunnelingprotocol (L2TP), or other Internet Protocol (IP) security protocols maybe used. In another exemplary embodiment, the processing nodes 110 maybe deployed at Internet service provider (ISP) nodes. The ISP nodes mayredirect subject traffic to the processing nodes 110 in a transparentproxy mode. Protected systems, such as the enterprise 200, may use amultiprotocol label switching (MPLS) class of service for indicating thesubject traffic that is to be redirected. For example, at the within theenterprise the access agent 180 may be configured to perform MPLSlabeling. In another transparent proxy mode exemplary embodiment, aprotected system, such as the enterprise 200, may identify theprocessing node 110 as a next hop router for communication with theexternal servers.

Generally, the distributed security system 100 may generally refer to anexemplary cloud-based security system. Cloud computing systems andmethods abstract away physical servers, storage, networking, etc. andinstead offer these as on-demand and elastic resources. The NationalInstitute of Standards and Technology (NIST) provides a concise andspecific definition which states cloud computing is a model for enablingconvenient, on-demand network access to a shared pool of configurablecomputing resources (e.g., networks, servers, storage, applications, andservices) that can be rapidly provisioned and released with minimalmanagement effort or service provider interaction. Cloud computingdiffers from the classic client-server model by providing applicationsfrom a server that are executed and managed by a client's web browser,with no installed client version of an application required.Centralization gives cloud service providers complete control over theversions of the browser-based applications provided to clients, whichremoves the need for version upgrades or license management onindividual client computing devices. The phrase “software as a service”(SaaS) is sometimes used to describe application programs offeredthrough cloud computing. A common shorthand for a provided cloudcomputing service (or even an aggregation of all existing cloudservices) is “the cloud.” The distributed security system 100 isillustrated herein as one exemplary embodiment of a cloud-based system,and those of ordinary skill in the art will recognize the cloud basedmobile device security and policy systems and methods contemplateoperation on any cloud based system.

Referring to FIG. 2, in an exemplary embodiment, a block diagramillustrates various components of the distributed security system 100 inmore detail. Although FIG. 2 illustrates only one representativecomponent processing node 110, authority node 120 and logging node 140,those of ordinary skill in the art will appreciate there may be many ofeach of the component nodes 110, 120 and 140 present in the system 100.A wide area network (WAN) 101, such as the Internet, or some othercombination of wired and/or wireless networks, communicatively couplesthe processing node 110, the authority node 120, and the logging node140 therebetween. The external systems 200, 220 and 230 likewisecommunicate over the WAN 101 with each other or other data providers andpublishers. Some or all of the data communication of each of theexternal systems 200, 220 and 230 may be processed through theprocessing node 110.

FIG. 2 also shows the enterprise 200 in more detail. The enterprise 200may, for example, include a firewall (FW) 202 protecting an internalnetwork that may include one or more enterprise servers 216, alightweight directory access protocol (LDAP) server 212, and other dataor data stores 214. Another firewall 203 may protect an enterprisesubnet that can include user computers 206 and 208 (e.g., laptop anddesktop computers). The enterprise 200 may communicate with the WAN 101through one or more network devices, such as a router, gateway, switch,etc. The LDAP server 212 may store, for example, user login credentialsfor registered users of the enterprise 200 system. Such credentials mayinclude a user identifiers, login passwords, and a login historyassociated with each user identifier. The other data stores 214 mayinclude sensitive information, such as bank records, medical records,trade secret information, or any other information warranting protectionby one or more security measures.

In an exemplary embodiment, a client access agent 180 a may be includedon a client computer 208. The client access agent 180 a may, forexample, facilitate security processing by providing a hash index offiles on the user computer 208 to a processing node 110 for malware,virus detection, etc. Other security operations may also be facilitatedby the access agent 180 a. In another exemplary embodiment, a serveraccess agent 180 may facilitate authentication functions with theprocessing node 110, e.g., by assigning tokens for passwords and sendingonly the tokens to the processing node 110 so that transmission ofpasswords beyond the network edge of the enterprise 200 is minimized.Other functions and processes may also be facilitated by the serveraccess agent 180 b. The computer device 220 and the mobile device 230may also store information warranting security measures, such aspersonal bank records, medical information, and login information, e.g.,login information to the server 206 of the enterprise 200, or to someother secured data provider server. The computer device 220 and themobile device 230 can also store information warranting securitymeasures, such as personal bank records, medical information, and logininformation, e.g., login information to a server 216 of the enterprise200, or to some other secured data provider server.

In an exemplary embodiment, the processing nodes 110 are external tonetwork edges of the external systems 200, 220 and 230. Each of theprocessing nodes 110 stores security policies 113 received from theauthority node 120 and monitors content items requested by or sent fromthe external systems 200, 220 and 230. In an exemplary embodiment, eachof the processing nodes 110 may also store a detection process filter112 and/or threat data 114 to facilitate the decision of whether acontent item should be processed for threat detection. A processing nodemanager 118 may manage each content item in accordance with the securitypolicy data 113, and the detection process filter 112 and/or threat data114, if stored at the processing node 110, so that security policies fora plurality of external systems in data communication with theprocessing node 110 are implemented external to the network edges foreach of the external systems 200, 220 and 230. For example, depending onthe classification resulting from the monitoring, the content item maybe allowed, precluded, or threat detected. In general, content itemsthat are already classified as “clean” or not posing a threat can beallowed, while those classified as “violating” may be precluded. Thosecontent items having an unknown status, e.g., content items that havenot been processed by the system 100, may be threat detected to classifythe content item according to threat classifications.

The processing node 110 may include a state manager 116A. The statemanager 116A may be used to maintain the authentication and theauthorization states of users that submit requests to the processingnode 110. Maintenance of the states through the state manager 116A mayminimize the number of authentication and authorization transactionsthat are necessary to process a request. The processing node 110 mayalso include an epoch processor 116B. The epoch processor 116B may beused to analyze authentication data that originated at the authoritynode 120. The epoch processor 116B may use an epoch ID to furthervalidate the authenticity of authentication data. The processing node110 may further include a source processor 116C. The source processor116C may be used to verify the source of authorization andauthentication data. The source processor 116C may identify improperlyobtained authorization and authentication data, enhancing the securityof the network. Collectively, the state manager 116A, the epochprocessor 116B, and the source processor 116C operate as data inspectionengines.

Because the amount of data being processed by the processing nodes 110may be substantial, the detection processing filter 112 may be used asthe first stage of an information lookup procedure. For example, thedetection processing filter 112 may be used as a front end to a lookingof the threat data 114. Content items may be mapped to index values ofthe detection processing filter 112 by a hash function that operates onan information key derived from the information item. The informationkey is hashed to generate an index value (i.e., a bit position). A valueof zero in a bit position in the guard table can indicate, for example,absence of information, while a one in that bit position can indicatepresence of information. Alternatively, a one could be used to representabsence, and a zero to represent presence. Each content item may have aninformation key that is hashed. For example, the processing node manager118 may identify the Uniform Resource Locator (URL) address of URLrequests as the information key and hash the URL address; or mayidentify the file name and the file size of an executable fileinformation key and hash the file name and file size of the executablefile. Hashing an information key to generate an index and checking a bitvalue at the index in the detection processing filter 112 generallyrequires less processing time than actually searching threat data 114.The use of the detection processing filter 112 may improve the failurequery (i.e., responding to a request for absent information) performanceof database queries and/or any general information queries. Because datastructures are generally optimized to access information that is presentin the structures, failure query performance has a greater effect on thetime required to process information searches for very rarely occurringitems, e.g., the presence of file information in a virus scan log or acache where many or most of the files transferred in a network have notbeen scanned or cached. Using the detection processing filter 112,however, the worst case additional cost is only on the order of one, andthus its use for most failure queries saves on the order of m log m,where m is the number of information records present in the threat data114.

The detection processing filter 112 thus improves performance of querieswhere the answer to a request for information is usually positive. Suchinstances may include, for example, whether a given file has been virusscanned, whether content at a given URL has been scanned forinappropriate (e.g., pornographic) content, whether a given fingerprintmatches any of a set of stored documents, and whether a checksumcorresponds to any of a set of stored documents. Thus, if the detectionprocessing filter 112 indicates that the content item has not beenprocessed, then a worst case null lookup operation into the threat data114 is avoided, and a threat detection can be implemented immediately.The detection processing filter 112 thus complements the threat data 114that capture positive information. In an exemplary embodiment, thedetection processing filter 112 may be a Bloom filter implemented by asingle hash function. The Bloom filter may be sparse table, i.e., thetables include many zeros and few ones, and the hash function is chosento minimize or eliminate false negatives which are, for example,instances where an information key is hashed to a bit position and thatbit position indicates that the requested information is absent when itis actually present.

In general, the authority node 120 includes a data store that storesmaster security policy data 123 for each of the external systems 200,220 and 230. An authority node manager 128 may be used to manage themaster security policy data 123, e.g., receive input from users of eachof the external systems defining different security policies, and maydistribute the master security policy data 123 to each of the processingnodes 110. The processing nodes 110 then store a local copy of thesecurity policy data 113. The authority node 120 may also store a masterdetection process filter 122. The detection processing filter 122 mayinclude data indicating whether content items have been processed by oneor more of the data inspection engines 116 in any of the processingnodes 110. The authority node manager 128 may be used to manage themaster detection processing filter 122, e.g., receive updates from aprocessing nodes 110 when the processing node 110 has processed acontent item and update the master detection processing filter 122. Forexample, the master detection processing filter 122 may be distributedto the processing nodes 110, which then store a local copy of thedetection processing filter 112.

In an exemplary embodiment, the authority node 120 may include an epochmanager 126. The epoch manager 126 may be used to generateauthentication data associated with an epoch ID. The epoch ID of theauthentication data is a verifiable attribute of the authentication datathat can be used to identify fraudulently created authentication data.In an exemplary embodiment, the detection processing filter 122 may be aguard table. The processing node 110 may, for example, use theinformation in the local detection processing filter 112 to quicklydetermine the presence and/or absence of information, e.g., whether aparticular URL has been checked for malware; whether a particularexecutable has been virus scanned, etc. The authority node 120 may alsostore master threat data 124. The master threat data 124 may classifycontent items by threat classifications, e.g., a list of known viruses,a list of known malware sites, spam email domains, list of known ordetected phishing sites, etc. The authority node manager 128 may be usedto manage the master threat data 124, e.g., receive updates from theprocessing nodes 110 when one of the processing nodes 110 has processeda content item and update the master threat data 124 with any pertinentresults. In some implementations, the master threat data 124 may bedistributed to the processing nodes 110, which then store a local copyof the threat data 114. In another exemplary embodiment, the authoritynode 120 may also monitor the health of each of the processing nodes110, e.g., the resource availability in each of the processing nodes110, detection of link failures, etc. Based on the observed health ofeach of the processing nodes 110, the authority node 120 may redirecttraffic among the processing nodes 110 and/or balance traffic among theprocessing nodes 110. Other remedial actions and processes may also befacilitated by the authority node 110.

The processing node 110 and the authority node 120 may be configuredaccording to one or more push and pull processes to manage content itemsaccording to security policy data 113 and/or 123, detection processfilters 112 and/or 122, and the threat data 114 and/or 124. In a threatdata push implementation, each of the processing nodes 110 stores policydata 113 and threat data 114. The processing node manager 118 determineswhether a content item requested by or transmitted from an externalsystem is classified by the threat data 114. If the content item isdetermined to be classified by the threat data 114, then the processingnode manager 118 may manage the content item according to the securityclassification of the content item and the security policy of theexternal system. If, however, the content item is determined to not beclassified by the threat data 114, then the processing node manager 118may cause one or more of the data inspection engines 117 to perform thethreat detection processes to classify the content item according to athreat classification. Once the content item is classified, theprocessing node manager 118 generates a threat data update that includesdata indicating the threat classification for the content item from thethreat detection process, and transmits the threat data update to anauthority node 120.

The authority node manager 128, in response to receiving the threat dataupdate, updates the master threat data 124 stored in the authority nodedata store according to the threat data update received from theprocessing node 110. In an exemplary embodiment, the authority nodemanager 128 may automatically transmit the updated threat data to theother processing nodes 110. Accordingly, threat data for new threats asthe new threats are encountered are automatically distributed to eachprocessing node 110. Upon receiving the new threat data from theauthority node 120, each of processing node managers 118 may store theupdated threat data in the locally stored threat data 114.

In a threat data pull and push implementation, each of the processingnodes 110 stores policy data 113 and threat data 114. The processingnode manager 118 determines whether a content item requested by ortransmitted from an external system is classified by the threat data114. If the content item is determined to be classified by the threatdata 114, then the processing node manager 118 may manage the contentitem according to the security classification of the content item andthe security policy of the external system. If, however, the contentitem is determined to not be classified by the threat data, then theprocessing node manager 118 may request responsive threat data for thecontent item from the authority node 120. Because processing a contentitem may consume valuable resource and time, in some implementations theprocessing node 110 may first check with the authority node 120 forthreat data 114 before committing such processing resources.

The authority node manager 128 may receive the responsive threat datarequest from the processing node 110 and may determine if the responsivethreat data is stored in the authority node data store. If responsivethreat data is stored in the master threat data 124, then the authoritynode manager 128 provide a reply that includes the responsive threatdata to the processing node 110 so that the processing node manager 118may manage the content item in accordance with the security policy data112 and the classification of the content item. Conversely, if theauthority node manager 128 determines that responsive threat data is notstored in the master threat data 124, then the authority node manager128 may provide a reply that does not include the responsive threat datato the processing node 110. In response, the processing node manager 118can cause one or more of the data inspection engines 116 to perform thethreat detection processes to classify the content item according to athreat classification. Once the content item is classified, theprocessing node manager 118 generates a threat data update that includesdata indicating the threat classification for the content item from thethreat detection process, and transmits the threat data update to anauthority node 120. The authority node manager 128 can then update themaster threat data 124. Thereafter, any future requests related toresponsive threat data for the content item from other processing nodes110 can be readily served with responsive threat data.

In a detection process filter and threat data push implementation, eachof the processing nodes 110 stores a detection process filter 112,policy data 113, and threat data 114. The processing node manager 118accesses the detection process filter 112 to determine whether thecontent item has been processed. If the processing node manager 118determines that the content item has been processed, it may determine ifthe content item is classified by the threat data 114. Because thedetection process filter 112 has the potential for a false positive, alookup in the threat data 114 may be implemented to ensure that a falsepositive has not occurred. The initial check of the detection processfilter 112, however, may eliminate many null queries to the threat data114, which, in turn, conserves system resources and increasesefficiency. If the content item is classified by the threat data 114,then the processing node manager 118 may manage the content item inaccordance with the security policy data 113 and the classification ofthe content item. Conversely, if the processing node manager 118determines that the content item is not classified by the threat data114, or if the processing node manager 118 initially determines throughthe detection process filter 112 that the content item is not classifiedby the threat data 114, then the processing node manager 118 may causeone or more of the data inspection engines 116 to perform the threatdetection processes to classify the content item according to a threatclassification. Once the content item is classified, the processing nodemanager 118 generates a threat data update that includes data indicatingthe threat classification for the content item from the threat detectionprocess, and transmits the threat data update to one of the authoritynodes 120.

The authority node manager 128, in turn, may update the master threatdata 124 and the master detection process filter 122 stored in theauthority node data store according to the threat data update receivedfrom the processing node 110. In an exemplary embodiment, the authoritynode manager 128 may automatically transmit the updated threat data anddetection processing filter to other processing nodes 110. Accordingly,threat data and the detection processing filter for new threats as thenew threats are encountered are automatically distributed to eachprocessing node 110, and each processing node 110 may update its localcopy of the detection processing filter 112 and threat data 114.

In a detection process filter and threat data pull and pushimplementation, each of the processing nodes 110 stores a detectionprocess filter 112, policy data 113, and threat data 114. The processingnode manager 118 accesses the detection process filter 112 to determinewhether the content item has been processed. If the processing nodemanager 118 determines that the content item has been processed, it maydetermine if the content item is classified by the threat data 114.Because the detection process filter 112 has the potential for a falsepositive, a lookup in the threat data 114 can be implemented to ensurethat a false positive has not occurred. The initial check of thedetection process filter 112, however, may eliminate many null queriesto the threat data 114, which, in turn, conserves system resources andincreases efficiency. If the processing node manager 118 determines thatthe content item has not been processed, it may request responsivethreat data for the content item from the authority node 120. Becauseprocessing a content item may consume valuable resource and time, insome implementations the processing node 110 may first check with theauthority node 120 for threat data 114 before committing such processingresources.

The authority node manager 128 may receive the responsive threat datarequest from the processing node 110 and may determine if the responsivethreat data is stored in the authority node data 120 store. Ifresponsive threat data is stored in the master threat data 124, then theauthority node manager 128 provides a reply that includes the responsivethreat data to the processing node 110 so that the processing nodemanager 118 can manage the content item in accordance with the securitypolicy data 112 and the classification of the content item, and furtherupdate the local detection processing filter 112. Conversely, if theauthority node manager 128 determines that responsive threat data is notstored in the master threat data 124, then the authority node manager128 may provide a reply that does not include the responsive threat datato the processing node 110. In response, the processing node manager 118may cause one or more of the data inspection engines 116 to perform thethreat detection processes to classify the content item according to athreat classification. Once the content item is classified, theprocessing node manager 118 generates a threat data update that includesdata indicating the threat classification for the content item from thethreat detection process, and transmits the threat data update to anauthority node 120. The authority node manager 128 may then update themaster threat data 124. Thereafter, any future requests for related toresponsive threat data for the content item from other processing nodes110 can be readily served with responsive threat data.

The various push and pull data exchange processes provided above areexemplary processes for which the threat data and/or detection processfilters may be updated in the system 100 of FIGS. 1 and 2. Other updateprocesses, however, are contemplated with the present invention. Thedata inspection engines 116, processing node manager 118, authority nodemanager 128, user interface manager 132, logging node manager 148, andauthority agent 180 may be realized by instructions that upon executioncause one or more processing devices to carry out the processes andfunctions described above. Such instructions can, for example, includeinterpreted instructions, such as script instructions, e.g., JavaScriptor ECMAScript instructions, or executable code, or other instructionsstored in a non-transitory computer readable medium. Other processingarchitectures can also be used, e.g., a combination of speciallydesigned hardware and software, for example.

Referring to FIG. 3, in an exemplary embodiment, a block diagramillustrates a server 300 which may be used in the system 100, in othersystems, or standalone. Any of the processing nodes 110, the authoritynodes 120, and the logging nodes 140 may be formed through one or moreservers 300. Further, the computer device 220, the mobile device 230,the servers 208, 216, etc. may include the server 300 or a similarstructure. The server 300 may be a digital computer that, in terms ofhardware architecture, generally includes a processor 302, input/output(I/O) interfaces 304, a network interface 306, a data store 308, andmemory 310. It should be appreciated by those of ordinary skill in theart that FIG. 3 depicts the server 300 in an oversimplified manner, anda practical embodiment may include additional components and suitablyconfigured processing logic to support known or conventional operatingfeatures that are not described in detail herein. The components (302,304, 306, 308, and 310) are communicatively coupled via a localinterface 312. The local interface 312 may be, for example but notlimited to, one or more buses or other wired or wireless connections, asis known in the art. The local interface 312 may have additionalelements, which are omitted for simplicity, such as controllers, buffers(caches), drivers, repeaters, and receivers, among many others, toenable communications. Further, the local interface 312 may includeaddress, control, and/or data connections to enable appropriatecommunications among the aforementioned components.

The processor 302 is a hardware device for executing softwareinstructions. The processor 302 may be any custom made or commerciallyavailable processor, a central processing unit (CPU), an auxiliaryprocessor among several processors associated with the server 300, asemiconductor-based microprocessor (in the form of a microchip or chipset), or generally any device for executing software instructions. Whenthe server 300 is in operation, the processor 302 is configured toexecute software stored within the memory 310, to communicate data toand from the memory 310, and to generally control operations of theserver 300 pursuant to the software instructions. The I/O interfaces 304may be used to receive user input from and/or for providing systemoutput to one or more devices or components. User input may be providedvia, for example, a keyboard, touch pad, and/or a mouse. System outputmay be provided via a display device and a printer (not shown). I/Ointerfaces 304 may include, for example, a serial port, a parallel port,a small computer system interface (SCSI), a serial ATA (SATA), a fibrechannel, Infiniband, iSCSI, a PCI Express interface (PCI-x), an infrared(IR) interface, a radio frequency (RF) interface, and/or a universalserial bus (USB) interface.

The network interface 306 may be used to enable the server 300 tocommunicate on a network, such as the Internet, the WAN 101, theenterprise 200, and the like, etc. The network interface 306 mayinclude, for example, an Ethernet card or adapter (e.g., 10 BaseT, FastEthernet, Gigabit Ethernet, 10 GbE) or a wireless local area network(WLAN) card or adapter (e.g., 802.11a/b/g/n). The network interface 306may include address, control, and/or data connections to enableappropriate communications on the network. A data store 308 may be usedto store data. The data store 308 may include any of volatile memoryelements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM,and the like)), nonvolatile memory elements (e.g., ROM, hard drive,tape, CDROM, and the like), and combinations thereof. Moreover, the datastore 308 may incorporate electronic, magnetic, optical, and/or othertypes of storage media. In one example, the data store 1208 may belocated internal to the server 300 such as, for example, an internalhard drive connected to the local interface 312 in the server 300.Additionally in another embodiment, the data store 308 may be locatedexternal to the server 300 such as, for example, an external hard driveconnected to the I/O interfaces 304 (e.g., SCSI or USB connection). In afurther embodiment, the data store 308 may be connected to the server300 through a network, such as, for example, a network attached fileserver.

The memory 310 may include any of volatile memory elements (e.g., randomaccess memory (RAM, such as DRAM, SRAM, SDRAM, etc.)), nonvolatilememory elements (e.g., ROM, hard drive, tape, CDROM, etc.), andcombinations thereof. Moreover, the memory 310 may incorporateelectronic, magnetic, optical, and/or other types of storage media. Notethat the memory 310 may have a distributed architecture, where variouscomponents are situated remotely from one another, but can be accessedby the processor 302. The software in memory 310 may include one or moresoftware programs, each of which includes an ordered listing ofexecutable instructions for implementing logical functions. The softwarein the memory 310 includes a suitable operating system (O/S) 314 and oneor more programs 316. The operating system 314 essentially controls theexecution of other computer programs, such as the one or more programs316, and provides scheduling, input-output control, file and datamanagement, memory management, and communication control and relatedservices. The one or more programs 316 may be configured to implementthe various processes, algorithms, methods, techniques, etc. describedherein.

Referring to FIG. 4, in an exemplary embodiment, a block diagramillustrates a mobile device 400, which may be used in the system 100 orthe like. The mobile device 400 can be a digital device that, in termsof hardware architecture, generally includes a processor 402,input/output (I/O) interfaces 404, a radio 406, a data store 408, andmemory 410. It should be appreciated by those of ordinary skill in theart that FIG. 4 depicts the mobile device 410 in an oversimplifiedmanner, and a practical embodiment may include additional components andsuitably configured processing logic to support known or conventionaloperating features that are not described in detail herein. Thecomponents (402, 404, 406, 408, and 402) are communicatively coupled viaa local interface 412. The local interface 412 can be, for example butnot limited to, one or more buses or other wired or wirelessconnections, as is known in the art. The local interface 412 can haveadditional elements, which are omitted for simplicity, such ascontrollers, buffers (caches), drivers, repeaters, and receivers, amongmany others, to enable communications. Further, the local interface 412may include address, control, and/or data connections to enableappropriate communications among the aforementioned components.

The processor 402 is a hardware device for executing softwareinstructions. The processor 402 can be any custom made or commerciallyavailable processor, a central processing unit (CPU), an auxiliaryprocessor among several processors associated with the mobile device410, a semiconductor-based microprocessor (in the form of a microchip orchip set), or generally any device for executing software instructions.When the mobile device 410 is in operation, the processor 402 isconfigured to execute software stored within the memory 410, tocommunicate data to and from the memory 410, and to generally controloperations of the mobile device 410 pursuant to the softwareinstructions. In an exemplary embodiment, the processor 402 may includea mobile optimized processor such as optimized for power consumption andmobile applications. The I/O interfaces 404 can be used to receive userinput from and/or for providing system output. User input can beprovided via, for example, a keypad, a touch screen, a scroll ball, ascroll bar, buttons, bar code scanner, and the like. System output canbe provided via a display device such as a liquid crystal display (LCD),touch screen, and the like. The I/O interfaces 404 can also include, forexample, a serial port, a parallel port, a small computer systeminterface (SCSI), an infrared (IR) interface, a radio frequency (RF)interface, a universal serial bus (USB) interface, and the like. The I/Ointerfaces 404 can include a graphical user interface (GUI) that enablesa user to interact with the mobile device 410. Additionally, the I/Ointerfaces 404 may further include an imaging device, i.e. camera, videocamera, etc.

The radio 406 enables wireless communication to an external accessdevice or network. Any number of suitable wireless data communicationprotocols, techniques, or methodologies can be supported by the radio406, including, without limitation: RF; IrDA (infrared); Bluetooth;ZigBee (and other variants of the IEEE 802.15 protocol); IEEE 802.11(any variation); IEEE 802.16 (WiMAX or any other variation); DirectSequence Spread Spectrum; Frequency Hopping Spread Spectrum; Long TermEvolution (LTE); cellular/wireless/cordless telecommunication protocols(e.g. 3G/4G, etc.); wireless home network communication protocols;paging network protocols; magnetic induction; satellite datacommunication protocols; wireless hospital or health care facilitynetwork protocols such as those operating in the WMTS bands; GPRS;proprietary wireless data communication protocols such as variants ofWireless USB; and any other protocols for wireless communication. Thedata store 408 may be used to store data. The data store 408 may includeany of volatile memory elements (e.g., random access memory (RAM, suchas DRAM, SRAM, SDRAM, and the like)), nonvolatile memory elements (e.g.,ROM, hard drive, tape, CDROM, and the like), and combinations thereof.Moreover, the data store 408 may incorporate electronic, magnetic,optical, and/or other types of storage media.

The memory 410 may include any of volatile memory elements (e.g., randomaccess memory (RAM, such as DRAM, SRAM, SDRAM, etc.)), nonvolatilememory elements (e.g., ROM, hard drive, etc.), and combinations thereof.Moreover, the memory 410 may incorporate electronic, magnetic, optical,and/or other types of storage media. Note that the memory 410 may have adistributed architecture, where various components are situated remotelyfrom one another, but can be accessed by the processor 402. The softwarein memory 410 can include one or more software programs, each of whichincludes an ordered listing of executable instructions for implementinglogical functions. In the example of FIG. 4, the software in the memory410 includes a suitable operating system (O/S) 414 and programs 416. Theoperating system 414 essentially controls the execution of othercomputer programs, and provides scheduling, input-output control, fileand data management, memory management, and communication control andrelated services. The programs 416 may include various applications,add-ons, etc. configured to provide end user functionality with themobile device 400. For example, exemplary programs 416 may include, butnot limited to, a web browser, social networking applications, streamingmedia applications, games, mapping and location applications, electronicmail applications, financial applications, and the like. In a typicalexample, the end user typically uses one or more of the programs 416along with a network such as the system 100.

Referring to FIG. 5, in an exemplary embodiment, a cloud system 500 isillustrated for implementing the DNS surrogation systems and methodssystems and methods and the like. The cloud system 500 includes one ormore cloud nodes (CN) 502 communicatively coupled to the Internet 504.The cloud nodes 502 may include the processing nodes 110, the server300, or the like. That is, the cloud system 500 may include thedistributed security system 100 or another implementation of a cloudbased system. In the cloud system 500, traffic from various locations(and various devices located therein) such as a regional office 510,headquarters 520, various employee's homes 530, mobile laptop 540, andmobile device 550 is redirected to the cloud through the cloud nodes502. That is, each of the locations 510, 520, 530, 540, 550 iscommunicatively coupled to the Internet 504 through the cloud nodes 502.The cloud system 500 may be configured to perform various functions suchas spam filtering, uniform resource locator (URL) filtering, antivirusprotection, bandwidth control, data loss prevention, zero dayvulnerability protection, web 2.0 features, and the like. In anexemplary embodiment, the cloud system 500 and the distributed securitysystem 100 may be viewed as Security-as-a-Service through the cloud.

In an exemplary embodiment, the cloud system 500 can be configured toprovide mobile device security and policy systems and methods. Themobile device 550 may be the mobile device 400, and may include commondevices such as smartphones, tablets, netbooks, personal digitalassistants, MP3 players, cell phones, e-book readers, and the like. Thecloud system 500 is configured to provide security and policyenforcement for devices including the mobile devices 550 in the cloud.Advantageously, the cloud system 500 avoids platform specific securityapps on the mobile devices 550, forwards web traffic through the cloudsystem 500, enables network administrators to define policies in thecloud, and enforces/cleans traffic in the cloud prior to delivery to themobile devices 550. Further, through the cloud system 500, networkadministrators may define user centric policies tied to users, notdevices, with the policies being applied regardless of the device usedby the user. The cloud system 500 provides 24×7 security with no needfor updates as the cloud system 500 is always up-to-date with currentthreats and without requiring device signature updates. Also, the cloudsystem 500 enables multiple enforcement points, centralized provisioningand logging, automatic traffic routing to a nearest cloud node 502,geographical distribution of the cloud nodes 502, policy shadowing ofusers which is dynamically available at the cloud nodes, etc.

In various exemplary embodiments, the cloud system 500 and/or thedistributed security system 100 can be used to perform DNS surrogation.Specifically, DNS surrogation can be a framework for distributed orcloud-based security/monitoring as is described herein. Endpointsecurity is no longer effective as deployments move to the cloud withusers accessing content from a plurality of devices in an anytime,anywhere connected manner. As such, cloud-based security is the mosteffective means to ensure network protection where different devices areused to access network resources. Traffic inspection in the distributedsecurity system 100 and the cloud-based system 500 is performed in anin-line manner, i.e. the processing nodes 110 and the cloud nodes 500are in the data path of connecting users. Another approach can include apassive approach to the data path. DNS is one of the most fundamental IPprotocols. With DNS surrogation as a technique, it is proposed to useDNS for dynamic routing of traffic, per user authentication and policyenforcement, and the like.

In conjunction with the cloud system 500 and/or the distributed securitysystem 100, various techniques can be used for monitoring which aredescribed on a sliding scale between always inline to never inline.First, in an always inline manner, all user traffic is between inlineproxies such as the processing nodes 110 or the cloud nodes 502 withoutexception. Here, DNS can be used as a forwarding mechanism to the inlineproxies. Second, in a somewhat always inline manner, all user trafficexcept for certain business partners or third parties is between inlineproxies such as the processing nodes 110 or the cloud nodes 502. Third,in an inline manner for most traffic, high bandwidth applications can beconfigured to bypass the inline proxies such as the processing nodes 110or the cloud nodes 502. Exemplary high bandwidth applications caninclude content streaming such as video (e.g., Netflix, Hulu, YouTube,etc.) or audio (e.g., Pandora, etc.). Fourth, in a mixed manner, inlinemonitoring can be used for “interesting” traffic as determined bysecurity policy with other traffic being direct. Fifth, in an almostnever inline manner, simple domain-level URL filtering can be used todetermine what is monitored inline. Finally, sixth, in a never inlinemanner, DNS augmented security can be used.

Referring to FIG. 6, in an exemplary embodiment, a network diagramillustrates a network 600 with a distributed security cloud 602providing DNS augmented security. The network 600 includes a user device604 connecting to the distributed security cloud 602 via an anycast DNSserver 606. The anycast DNS server 606 can be a server such as theserver 300 of FIG. 3. Also, the anycast DNS server 606 can be theprocessing node 110, the cloud node 502, etc. The distributed securitycloud 602 includes the anycast DNS server 606, policy data 608, and aninline proxy 610. The inline proxy 610 can include the processing node110, the cloud node 502, etc. In operation, the user device 604 isconfigured with a DNS entry of the anycast DNS server 606, and theanycast DNS server 606 can perform DNS surrogation as is describedherein. The distributed security cloud 602 utilizes the anycast DNSserver 606, the policy data 608, and the inline proxy 610 to perform theDNS augmented security.

The network 600 illustrates the DNS augmented security where DNSinformation is used as follows. First, at a step 610, the user device604 requests a DNS lookup of a site, e.g. “what is the IP address ofsite.com?” from the anycast DNS server 606. The anycast DNS server 606accesses the policy data 608 to determine the policy associated with thesite at step 612. The anycast DNS server 606 returns the IP address ofthe site based on the appropriate policy at step 614. The policy data608 determines if the site either goes direct (step 616) to theInternet, is inspected by the inline proxy (step 618), or is blocked perpolicy (step 620). Here, the anycast DNS server 606 returns the IPaddress with additional information if the site is inspected or blocked.For example, if the anycast DNS server 606 determines the access isdirect, the anycast DNS server 606 simply returns the IP address of thesite. If the anycast DNS server 606 determines the site is blocked orinspected, the anycast DNS server 606 returns the IP address to theinline proxy 610 with additional information. The inline proxy 610 canblock the site or provide fully inline proxied traffic to the site (step622) after performing monitoring for security.

The DNS augmented security advantageously is protocol and applicationagnostic providing visibility and control across virtually allInternet-bound traffic. For example, DNS-based protocols includeInternet Relay Chat (IRC), Session Initiation Protocol (SIP), HypertextTransfer Protocol (HTTP), HTTP Secure (HTTPS), Post Office Protocol v3(POP3), Internet Message Access Protocol (IMAP), etc. Further, emergingthreats are utilizing DNS today especially Botnets and advancedpersistent threats (APTs). For example, Fast flux is a DNS techniqueused to hide phishing and malware delivery sites behind an ever-changingnetwork of compromised hosts acting as proxies. The DNS augmentedsecurity provides deployment flexibility when full inline monitoring isnot feasible. For example, this can be utilized in highly distributedwith high bandwidth environments, in locations with challenging InternetAccess, etc. The DNS augmented security can provide URL filtering,white/black list enforcement, etc. for enhanced security without contentfiltering. In this manner, the network 600 can be used with thedistributed security system 100 and the cloud system 500 to providecloud-based security without requiring full inline connectivity.

Referring to FIG. 7, in an exemplary embodiment, a flow diagramillustrates a DNS surrogation method 700. The DNS surrogation method 700operates between a client device 602, a DNS server 604, a DNS surrogateserver 702, and an authoritative DNS server 704. For example, the DNSsurrogation method 700 can be implemented by the distributed securitysystem 100, the cloud system 500, the network 600, or the like. Theclient device 602 can be any user equipment including, withoutlimitation, the enterprise 200, the computer device 220, the mobiledevice 230, the mobile device 400, a smart phone, a cell phone, atablet, a net book, an ultra-book, a laptop, a desktop, or any digitalcomputing device networked to the DNS server 604. The DNS server 604,the DNS surrogate server 702, and the authoritative DNS server 704 caninclude the server 300 or the like. Prior to operation of the DNSsurrogation method 700 (or any DNS requests), the client device 602 isconfigured to use the DNS server 604 under associated network settings.For example, the client device 602 is configured with the IP address ofthe DNS server 604 as its DNS server (e.g., 8.34.34.34 and 8.35.35.35).In this manner, the DNS server 604 is configured as the recursive DNSserver for the client device 602.

The DNS surrogation method 700 includes the client device 602 requestsresolution of a particular domain name using the associated configuredrecursive DNS server 604 (step 711). The receiving DNS server 602performs a policy lookup based on several factors including the clientlocation, configuration policy, the status of the available surrogates,the locality of those surrogates, etc. For example, the policy lookupcan be through the policy data 608. If a decision to surrogate is madethe request from the client device 602 is surrogated to a particularsurrogate. For example, the receiving DNS server 604 provides therequest from the client device 602 to the DNS surrogate server 702 (step712). The DNS surrogate server 702 receives the request and performsrecursion to get the requested resolution which includes sending arequest to the authoritative DNS server 704 for the domain name which isbeing resolved (step 713). The authoritative DNS server 704 receives therequest from the DNS surrogate server 702 allowing it to provide resultsbased on the location/source IP address of the DNS surrogate server 702as opposed to the receiving DNS server 604 (step 714). Finally, alocalized/optimized/differentiated resolution (based on the DNSsurrogate server 702) is provided directly back to the client device 602(step 715). The DNS surrogation method 700 also allows for a lightweightDNS-based policy lookup occurring while leaving the actual process ofresolution to take place on the DNS surrogate server 702. In this modelthe DNS surrogate server 702 can actually be the client device 602itself that is receiving DNS-based policy and control. The clientsurrogate could be a mobile phone, laptop, virtual machine, appliance,etc.

Referring to FIG. 8, in an exemplary embodiment, a flow diagramillustrates a DNS surrogation method 800 showing activity in the network600 and amongst the receiving DNS server 604 and the DNS surrogateserver 702. The DNS surrogation method 800 can be implemented with theDNS surrogation method 700. The DNS surrogation method 800 includes fivetypes of DNS requests 802, 804, 806, 808, 810. First, a DNS request 802can arrive at the DNS surrogate server 702 where a direct server returnis not possible. Second, a DNS request 804 can arrive at the DNSsurrogate server 702 where a direct server return is possible. Third, aDNS request 806 can be an ordinary DNS request. Fourth, a DNS request808 can arrive that must be surrogated where the DNS surrogate server702 cannot do a direct server return. Fifth, a DNS request 810 canarrive that must be surrogated where the DNS surrogate server 702 can doa direct server return.

The DNS surrogation method 800 includes the DNS request 802, 804, 806,808, 810 arriving (step 821) and verification is performed (step 822).Optionally, the DNS surrogation method 800 can perform IP throttlingsuch as with UDP (step 823). The DNS surrogation method 800 canasynchronously retrieve policy for the DNS request 802, 804, 806, 808,810 (step 824). For example, the policy can be contained in the policydata 608 and can determine which type the DNS request 802, 804, 806,808, 810. The DNS surrogation method 800 can select a cache based ongeography (step 825) and check the selected cache (step 826). DNS cacheservers store DNS query results for a period of time determined in theconfiguration (time-to-live) of the domain name record in question. Allof the steps 821-827 can be performed for all of the different types ofDNS request 802, 804, 806, 808, 810.

Next, the DNS surrogation method 800 determines if the type of DNSrequest 802, 804, 806, 808, 810 needs to be surrogated (step 827). TheDNS requests 802, 804, 806 do not get surrogated, and the DNS requests808, 810 do get surrogated. For the DNS requests 802, 804, 806, the DNSsurrogation method 800 includes resolving the name of the DNS requests802, 804, 806 (step 828). For the DNS requests 808, 810, the DNSsurrogation method 800 performs a synchronous policy retrieval based onthe DNS requests 808, 810 (step 829). Again, this can include the policydata 608. Here, the DNS surrogation method 800 can obtain informationabout which DNS surrogate server 702 to use, etc. With the policyretrieval, the DNS surrogation method 800 can perform rate limiting andtransfer (step 830) and send the DNS request 808, 810 and the retrievedpolicy to the DNS surrogate server 702 (step 831). The DNS surrogationmethod 800 includes obtaining a result from the DNS surrogate server702, the result being the DNS lookup of the DNS request 808, 810 (step832).

Subsequent to steps 828, 832, the DNS surrogation method 800 can fillthe cache (step 833). Next, the DNS surrogation method 800 determines ifthe DNS request 802, 804, 806, 808, 810 requires a response (step 834).The DNS requests 802, 804, 806, 808 require a response whereas the DNSrequest 810 does not. For the DNS requests 802, 804, 806, the DNSsurrogation method 800 performs a synchronous policy retrieval (step835). Subsequent to the step 835 and for the DNS requests 804, 806, 810,the DNS surrogation method 800 checks policies based on the policyretrieval (step 836) and responds based thereon (step 837). For example,a policy can include IP throttling. For all of the DNS request 802, 804,806, 808, 810, the DNS surrogation method 800 determines if the DNSsurrogate server 702 needs a response (step 838), and for the DNSrequests 802, 804, the DNS surrogation method 800 sends the result tothe DNS surrogate server 702. Finally, the DNS surrogation method 800performs logging (step 840) and the DNS requests are complete (step841).

It will be appreciated that some exemplary embodiments described hereinmay include one or more generic or specialized processors (“one or moreprocessors”) such as microprocessors, digital signal processors,customized processors, and field programmable gate arrays (FPGAs) andunique stored program instructions (including both software andfirmware) that control the one or more processors to implement, inconjunction with certain non-processor circuits, some, most, or all ofthe functions of the methods and/or systems described herein.Alternatively, some or all functions may be implemented by a statemachine that has no stored program instructions, or in one or moreapplication specific integrated circuits (ASICs), in which each functionor some combinations of certain of the functions are implemented ascustom logic. Of course, a combination of the aforementioned approachesmay be used. Moreover, some exemplary embodiments may be implemented asa non-transitory computer-readable storage medium having computerreadable code stored thereon for programming a computer, server,appliance, device, etc. each of which may include a processor to performmethods as described and claimed herein. Examples of suchcomputer-readable storage mediums include, but are not limited to, ahard disk, an optical storage device, a magnetic storage device, a ROM(Read Only Memory), a PROM (Programmable Read Only Memory), an EPROM(Erasable Programmable Read Only Memory), an EEPROM (ElectricallyErasable Programmable Read Only Memory), Flash memory, and the like.When stored in the non-transitory computer readable medium, software caninclude instructions executable by a processor that, in response to suchexecution, cause a processor or any other circuitry to perform a set ofoperations, steps, methods, processes, algorithms, etc.

Although the present disclosure has been illustrated and describedherein with reference to preferred embodiments and specific examplesthereof, it will be readily apparent to those of ordinary skill in theart that other embodiments and examples may perform similar functionsand/or achieve like results. All such equivalent embodiments andexamples are within the spirit and scope of the present disclosure, arecontemplated thereby, and are intended to be covered by the followingclaims.

What is claimed is:
 1. A method implemented in a cloud network, themethod comprising: receiving a Domain Name System (DNS) request;determining, based on a policy associated with the DNS request, whetherthe DNS request is to be surrogated, the policy defining which types ofDNS requests are to be surrogated based on 1) a DNS request arrivingwhere surrogation is possible and a direct server return is notpossible, 2) a DNS request arriving where surrogation is possible and adirect server return is possible, 3) an ordinary DNS request, 4) a DNSrequest arriving that must be surrogated where a direct server return isnot possible, and 5) a DNS request arriving that is must be surrogatedwhere a direct return is possible; relaying, responsive to thedetermination that the DNS request is to be surrogated, the DNS requestto a surrogate of a plurality of surrogates that resolves the DNSrequest by performing recursion to determine a result of the DNSresolution, wherein one or more of the plurality of surrogates compriseclients receiving service from the cloud network, wherein the clientsare user equipment associated with a user that is configured for use ofthe service provided by the cloud network and the clients are thesurrogates performing the DNS resolution, and wherein the policyincludes evaluation of status of the plurality of surrogates andlocation; and responsive to DNS resolution performed by the surrogate,providing the result of the DNS resolution as a response to the DNSrequest.
 2. The method of claim 1, wherein the surrogate provides theresult to the DNS request independent of a device receiving the DNSrequest.
 3. The method of claim 1, wherein the surrogate is determinedbased on the policy.
 4. The method of claim 1, wherein the surrogate isdetermined based on a location of a user device associated with the DNSrequest.
 5. The method of claim 1, wherein the surrogate is configuredto provide a request to an authoritative DNS server associated with adomain name of the DNS request.
 6. The method of claim 1, wherein theresult of the DNS resolution is based on a location or source InternetProtocol address of the surrogate instead of based on a DNS serverperforming the receiving.
 7. The method of claim 1, wherein the servicefrom the cloud network comprises security monitoring.
 8. A Domain NameServer (DNS) system in a cloud network, comprising: a network interface;a processor communicatively coupled to the network interface; memorystoring instructions that, when executed, cause the processor to:receive a DNS request; determine, based on a policy associated with theDNS request, whether the DNS request is to be surrogated, the policydefining which types of DNS requests are to be surrogated based on 1) aDNS request arriving where surrogation is possible and direct server isnot possible, 2) a DNS request arriving where surrogation is possibleand a direct server return is possible, 3) an ordinary DNS request, 4) aDNS request arriving that must be surrogated where a direct serverreturn is not possible, and 5) a DNS request arriving that is must besurrogated where a direct server return is possible; and relay,responsive to the determination that the DNS request is to besurrogated, the DNS request to a surrogate of a plurality of surrogates,wherein the surrogate resolves the DNS request by performing recursionto determine a result of the DNS resolution, wherein one or more of theplurality of surrogates comprise clients receiving service from thecloud network, wherein the clients are user equipment associated with auser that is configured for use of the service provided by the cloudnetwork and the clients are the surrogates performing the DNSresolution, and wherein the policy includes evaluation of status of theplurality of surrogates and location, wherein, responsive to DNSresolution performed by the surrogate, the result of the DNS resolutionis provided as a response to the DNS request.
 9. The DNS system of claim8, wherein the surrogate provides the result to the DNS requestindependent of a device receiving the DNS request.
 10. The DNS system ofclaim 8, wherein the surrogate is determined based on a location of auser device associated with the DNS request.
 11. The DNS system of claim8, wherein the surrogate is configured to provide a request to anauthoritative DNS server associated with a domain name of the DNSrequest.
 12. The DNS system of claim 8, wherein the result of the DNSresolution is based on a location or source Internet Protocol address ofthe surrogate instead of based on a DNS server performing the receiving.13. The DNS system of claim 8, wherein the service from the cloudnetwork comprises security monitoring.
 14. A user device configured toreceive a service from a cloud network, comprising: a network interface;a processor communicatively coupled to the network interface; memorystoring instructions that, when executed, cause the processor to:communicate with the cloud network for the service provided by the cloudnetwork; receive, responsive to a Domain Name Server (DNS) requestreceived by the cloud network and responsive to a determination, basedon a policy associated with the DNS request, that the DNS request is tobe surrogated, wherein the policy defines which types of DNS requestsare to be surrogated and includes evaluation of status of the surrogateand location, the types of DNS requests that are to be surrogated basedon 1) a DNS request arriving where surrogation is possible and a directserver return is not possible, 2) a DNS request arriving wheresurrogation is possible and a direct server return is possible, 3) anordinary DNS request, 4) a DNS request arriving that must be surrogatedwhere a direct server return is not possible, and 5) a DNS requestarriving that is must be surrogated where a direct server return ispossible, a DNS surrogation request from the cloud network, wherein theuser device is user equipment associated with a user that is configuredfor use of the service and is further configured to act as a DNSsurrogate for the cloud network in lieu of a DNS server receiving theDNS request; perform a DNS resolution of the DNS request includingrecursion to determine a result of the DNS resolution; and provide aresult of the DNS resolution as a response to the DNS request.
 15. Theuser device of claim 14, wherein the user device provides the result tothe DNS request independent of a device receiving the DNS request. 16.The user device of claim 14, wherein the DNS surrogation request isdetermined based on a location of a user device associated with the DNSrequest.
 17. The user device of claim 14, wherein the result of the DNSresolution is based on a location or source Internet Protocol address ofthe user device instead of based on a DNS server which received the DNSrequest.